TechTalk

Census 2000 Redistricting Data (Public Law 94-171) ASCII text data files

Some things to consider
Deciding which files to use
Uncompressing the data files
Using Microsoft Access (tm)

SAS program (3/02/2001 - converts ASCII text data files to SAS datasets)
Technical documentation [, 3,994 KB]

Some things to consider

The geographic file is fixed width with no field delimiters; Both data files are comma delimited. None of the files contain header records (a first record with field names).

The only relationship between any one file (geographic or data) and another is the field LOGRECNO (logical record number). This field is a unique key. There is a one to one correspondence based on LOGRECNO between the geographic file and both data files.

The directions for unzipping the data files given below apply only to PKZIP for Windows 4.0 or higher (available from pkware.com ).

Some data files are too large to import into Access 97. More recent versions of Access can be used for these cases.

Access 2000 does not recognize the "uf1" file name extension (not related to file format). Change the file name extensions of the uncompressed ASCII text data files from "uf1" to "txt". This must be done from a DOS prompt (using the rename command) for most versions of Windows.

DOS prompt

 Volume in drive C has no label
 Volume Serial Number is 1057-18CE
 Directory of C:\sf1ascii

DEGEO    UF1   8,161,404  09-13-01 12:04p degeo.uf1
DE00001  UF1   9,813,749  09-13-01 12:05p de00001.uf1
         2 file(s)   17,975,153 bytes
         0 dir(s)   134,721,536 bytes free

C:\sf1ascii>rename *.uf1 *.txt

C:\sf1ascii>dir *.txt

 Volume in drive C has no label
 Volume Serial Number is 1057-18CE
 Directory of C:\sf1ascii

DE00001  TXT  9,813,749 09-13-01 12:05p de00001.txt
DEGEO    TXT  8,161,404 09-13-01 12:04p degeo.txt
         2 file(s)   17,975,153 bytes
         0 dir(s)   134,721,536 bytes free

C:\sf1ascii>

[Back to Top]Deciding which files to use

A data set for a state consists of a geographic file and two data files. The data was split into multiple files due to a limit in the number of fields allowed per record in most popular database and spreadsheet programs.

All geographic data identifiers (area names, FIPS codes, etc.) are in the geographic file only. See chapter 3: Subject Locator in the technical documentation to identify tables you want. Go to Chapter 2: How to Use This File to identify the data files(s) that contain these tables. Also, see file layouts ( in ASCII format).

Technical documentation [, 3,994 KB]

[Back to Top] Uncompressing the data files

The data files contain a line feed character only at the end of each record. For successful use with many programs running in a Windows environment¹, these files need to be modified to use the ASCII carriage return/line feed sequence, chr(13) + chr(10), as a record terminator. PKZIP for Windows version 4.00 instructions appear below.

1. Open file
2. Select Extract option from tool bar.
3. Click the Options button.
4. Select "DOS - convert to CR/LF" under the Miscellaneous section.

Select "None - no conversion" under the Miscellaneous section to unzip file structures downloaded from this page.

¹ Your normal unzipping program and procedures can be used if using SAS instead of database software like Access or spreadsheet software like Excel.

[Back to Top]Using Microsoft Access (tm)

Redistricting Data (Public Law 94-171) database [ZIP, 32 KB] (Access 97 format) and then open it in Microsoft Access. Follow procedure to use this database with the ASCII text data files.